An example of this procedure http://www.selleckchem.com/products/mek162.html is described in this paper.2.?Basic Theory and design principles for a ten-port reflectometer2.1. Six-port reflectometer reviewA six-port Inhibitors,Modulators,Libraries reflectometer consists of a simple circuit with two ports for signal input Inhibitors,Modulators,Libraries and output, and four ports with their corresponding Carfilzomib power detectors that sample the standing wave within the transmission line. The input port is connected to the EM source and the output port is connected to the load. This load can generate a mismatch that leads to reflections whose magnitude must be measured by the reflectometer.Figure 1 shows a simplified scheme of a six-port reflectometer, where ai signals go always into the ith port and bi signals go out from the ith port.
Ports ranging from 3 to 6 are matched and therefore no reflected wave is considered there.
In this scheme, Port 1 is the input port where the EM source is connected, whereas Port 2 is the output port of the sensor.Figure 1.Six-port reflectometer scheme.The Inhibitors,Modulators,Libraries complex reflection coefficient (��), also called S11 scattering parameter, provides a relationship between the incident wave amplitude at Port Inhibitors,Modulators,Libraries 1 (a1) and the reflected wave amplitude (b1) at the input port (Port Inhibitors,Modulators,Libraries 1 in Figure 1). The bigger the magnitude of ��, the more energy is reflected to the EM source, thus less energy is absorbed by the load.A numerical relationship can be obtained from the power detected at Ports 3 to 6 to determine the reflection coefficient in the load.
This numerical expression combines the value of nine complex parameters, very sensitive to measurement noise and non-linearities, in order to determine the desired reflection coefficient value.
The equation system shown in (1) relates the incident and reflected wave amplitudes Inhibitors,Modulators,Libraries at Port 2 to the sampling amplitudes. The calibration procedure of this six-port reflectometer is based on finding the numerical solution for this equation system, Inhibitors,Modulators,Libraries where Mi and Ni are complex constants. As described earlier, several calibration methods and load standards can be used.b3=M3?a2+N3?b2b4=M4?a2+N4?b2b5=M5?a2+N5?b2b6=M6?a2+N6?b2}(1)To solve this system, eight linear equations must be considered. A theoretical linear dependence of all important parameters could be obtained if noise, measurement perturbations Drug_discovery and non-linear effects are not considered.
However, Inhibitors,Modulators,Libraries the calibration procedure becomes a hard task under real conditions AV-951 where the above mentioned effects can not be neglected.
Additionally, this configuration cannot be used when either any of the power detectors is broken, damaged or saturated. This sellectchem is due to the fact that the six-port uses the minimum amount of detecting ports that are required to find a precise solution. This may lead to delays both in laboratory measurements or industrial monitoring since the power detector must be repaired or changed, and then the whole device recalibrated, before being able to measure again.2.2.